Imatinib Mesylate (STI571) Abrogates the Resistance to Doxorubicin in K562 Chronic Myeloid Leukemia Cells by Inhibition of BCR/ABL Kinase-Mediated DNA Repair.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1525-1525
Author(s):  
Ireneusz Majsterek ◽  
Janusz Blasiak ◽  
Artur Slupianek ◽  
Tomasz Skorski
Keyword(s):  
Drug Resistance ◽  
Dna Repair ◽  
Imatinib Mesylate ◽  
Lymphoblastic Leukemia ◽  
Specific Inhibitor ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Abl Kinase ◽  
Kinetics Of

Abstract Imatinib mesylate (STI571), a specific inhibitor of the BCR/ABL tyrosine kinase, exhibits potent antileukemic effects in the treatment of chronic myelogenous leukemia (CML). However, the precise mechanisms by which inhibition of BCR/ABL activity results in pharmacological responses remain unknown. BCR/ABL-positive human CML cells resistant to doxorubicin K562doxoR and their sensitive K562doxoS counterparts were used to determine the mechanism by which the STI571 inhibitor may overcome drug resistance. K562 wild type cells and CCRF-CEM lymphoblastic leukemia cells without BCR/ABL were used as controls. We examined kinetics of DNA repair after cell treatment with the drug by the alkaline comet assay. MTT assay was used to estimate resistance against doxorubicin and Western Blot analysis with Crk-L antibody was performed to evaluate BCR/ABL kinase inhibition by STI571. We provide evidence that treatment of CML-derived BCR/ABL-expressing leukemia K562 cells with STI571 results in the inhibition of DNA repair and abrogation of the resistance of these cells to doxorubicin. We found that doxorubicin-resistant K562doxoR cells exhibited accelerated kinetics of DNA repair in comparison to doxorubicin-sensitive K562doxoS cells. Inhibition of BCR/ABL kinase in K562doxoR cells with 1 μM STI571 decreased the kinetics of DNA repair and abrogated drug resistance. The results suggest that STI571-mediated inhibition of BCR/ABL kinase activity can affect the effectiveness of the DNA repair pathways, which in turn may enhance drug sensitivity of leukemia cells.

Identification and Functional Significance of Genes Regulated by Structurally Different ABL Kinase Inhibitors.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2860-2860
Author(s):  
Kousuke Nunoda ◽  
Tetsuzo Tauchi ◽  
Tomoiku Takaku ◽  
Masahiko Sumi ◽  
Seiichi Okabe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Inhibition ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Specific Inhibitor ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Altered Expression ◽  
Abl Kinase ◽  
Abl Kinase Inhibitors

Abstract Imatinib is an ABL-specific inhibitor that binds with high affinity to the inactive conformation of the BCR-ABL tyrosine kinase and has been shown to be effective in the treatment of chronic myelogenous leukemia. Dasatinib is an ATP-competitive, dual-spesific SRC and ABL kinase inhibitor that can bind BCR-ABL in both the active and inactive conformations. From a clinical stand point, dasatinib is particular attractive because it has been shown to induce hematologic and cytogenetic responses in imatinib-resistant CML patients. In the view of the fact that the combination of imatinib and dasatinib shows the additive/synergistic growth inhibition on a wild type p210 BCR-ABL expressing cells, we reasoned that these ABL kinase inhibitors might induce the different molecular pathways. To address this question, we used DNA microarrays to identify genes whose transcription was altered by imatinib and dasatinib. K562 cells were cultured with imatinib or dasatinib for 16 hrs, and gene expression data was obtained from three independent microarray hybridizations. Almost all of the imatinib- and dasatinib- responsive genes appeared to be similarly increased or decreased in K562 cells; however, small subsets of genes were identified as selectively altered expression by either imatinib or dasatinib. The genes whose expression was affected by imatinib and dasatinib were categorized into different functional groups based on their biological function, and genes in the cell proliferation and apoptosis categories were examined in detail. Imatinib and dasatinib affected the expression of several cyclin-dependent kinases (CDK2, CDK4, CDK6, CDK8, and CDK9), cell division cycle genes (CDC6, CDC7, CDC25C, and CDC34), and cyclones (cyclin A2, C, D2, D3, E1, E2, F, G1, G2, and H). Imatinib and dasatinib also modulated the expression of apoptosis-related genes including APAF1, BAK1, BCL2, BCL10, MCL1, CASP3, and CASP6). One of the distinct genes which are selectively modulated by dasatinib are CDK2 and CDK8, which had a maximal fold reduction of <8-fold in microarray screen. Immunoblotting confirmed that gene expression changes induced only by dasatinib correlated with changes in protein expression. To assess the functional importance of dasatinib regulated genes, we used RNA interference to determine whether reduction of CDK2 and CDK8 affected the growth inhibition. The siRNA to CDK2 or CDK8 specifically reduced cdk2 or cdk8 in K562 cells. K562 cells pretreated with CDK2 or CDK8 siRNA showed the additive growth inhibition with imatinib but not with dasatinib. These finding demonstrate that the additive/synergistic growth inhibition by imatinib and dasatinib may be mediated by CDK2 and CDK8.

scholarly journals Vorinostat synergistically potentiates MK-0457 lethality in chronic myelogenous leukemia cells sensitive and resistant to imatinib mesylate

Blood ◽  
2008 ◽  
Vol 112 (3) ◽  
pp. 793-804 ◽  
Author(s):  
Yun Dai ◽  
Shuang Chen ◽  
Charis A. Venditti ◽  
Xin-Yan Pei ◽  
Tri K. Nguyen ◽  
...  
Keyword(s):  
Imatinib Mesylate ◽  
Chronic Myelogenous Leukemia ◽  
Kinase Inhibitor ◽  
K562 Cells ◽  
Aurora Kinase ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Highly Active ◽  
Deacetylase Inhibitor ◽  
T315i Mutation

Abstract Interactions between the dual Bcr/Abl and aurora kinase inhibitor MK-0457 and the histone deacetylase inhibitor vorinostat were examined in Bcr/Abl+ leukemia cells, including those resistant to imatinib mesylate (IM), particularly those with the T315I mutation. Coadministration of vorinostat dramatically increased MK-0457 lethality in K562 and LAMA84 cells. Notably, the MK-0457/vorinostat regimen was highly active against primary CD34+ chronic myelogenous leukemia (CML) cells and Ba/F3 cells bearing various Bcr/Abl mutations (ie, T315I, E255K, and M351T), as well as IM-resistant K562 cells exhibiting Bcr/Abl-independent, Lyn-dependent resistance. These events were associated with inactivation and down-regulation of wild-type (wt) and mutated Bcr/Abl (particularly T315I). Moreover, treatment with MK-0457 resulted in accumulation of cells with 4N or more DNA content, whereas coadministration of vorinostat markedly enhanced aurora kinase inhibition by MK-0457, and preferentially killed polyploid cells. Furthermore, vorinostat also interacted with a selective inhibitor of aurora kinase A and B to potentiate apoptosis without modifying Bcr/Abl activity. Finally, vorinostat markedly induced Bim expression, while blockade of Bim induction by siRNA dramatically diminished the capacity of this agent to potentiate MK-0457 lethality. Together, these findings indicate that vorinostat strikingly increases MK-0457 activity against IM-sensitive and -resistant CML cells through inactivation of Bcr/Abl and aurora kinases, as well as by induction of Bim.

The Effect of siRNA Down-Regulating XIAP On the Apoptosis and Chemo-Sensitivity of K562 Cells in Vitro.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 5053-5053
Author(s):  
Shuangfeng Xie ◽  
Songmei Yin ◽  
Dan Li ◽  
Danian Nie ◽  
Yiqing Li ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Apoptosis ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Inhibitor Of Apoptosis ◽  
Apoptotic Cells ◽  
Transfected Cells ◽  
Apoptosis Protein ◽  
Significant Difference

Abstract Abstract 5053 Introduction Failure for chemotherapy in leukemia patients is often due to innate or acquired multi-drug resistance of leukemia cells. The X-linked inhibitor of apoptosis protein (XIAP) is a potent inhibitor of apoptosis and is also involved in drug resistance. The relationship between XIAP and drug resistance is not fully clarified. Here, we manipulated the expression of XIAP in K562 human chronic myelogenous leukemia cells and explore the changes in cell apoptosis and sensitivity to cytarabin. Methods Small interfering RNA (siRNA) targeting XIAP was created, K562 cells were either transfected with XIAP siRNA or control siRNA by Nucleofector transfection. The siRNAs were labelled with Cy3. Real-time RT-PCR and Western blot were used to determine the expression of XIAP in K562 cells. Flow cytometry was used to detect apoptotic cells and 50% inhibiting concentration (IC50) of cytarabin was also determined. Results The transfection rate was 87% in general. The transfection was also confirmed by fluorescence microscopy. After 48h, the expression levels of XIAP mRNA and protein were much lower in XIAP siRNA-transfected cells than in control siRNA-transfected cells (mRNA, 0.37±0.10 vs. 1.41±0.13, P<0.05 ; protein, 0.39±0.03 vs. 0.99±0.08, P<0.05). There was no significant difference in the fractions of apoptotic cells between these two groups at 48h after transfection (37.04%±1.77% vs. 47.43%±1.13%, P>0.05). Cytarabin was added in different concentrations right after Nucleotransfection. After 48h, the IC50 of Cytarabin in the XIAP siRNA-transfected cells was 2.28-fold lower than that in the control siRNA-transfected cells (82.60±21.56μg/ml vs. 188.67±44.48μg/ml, P<0.05). The percentage of apoptotic cells was much higher in the XIAP knockdown cells than in the control cells (47.43%±1.13% vs. 37.04%±1.77% P<0.05). Conclusions XIAP siRNA can specifically down-regulate the expressions of XIAP mRNA and protein, promote the drug-sensitivity to cytarabin and increase the cell apoptosis in K562 cells. This might be a novel choice for leukemia treatment. Disclosures No relevant conflicts of interest to declare.

scholarly journals A microfluidic device enabling drug resistance analysis of leukemia cells via coupled dielectrophoretic detection and impedimetric counting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yağmur Demircan Yalçın ◽  
Taylan Berkin Töral ◽  
Sertan Sukas ◽  
Ender Yıldırım ◽  
Özge Zorlu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
K562 Cells ◽  
Leukemia Cells ◽  
Drug Resistant ◽  
Wild Type ◽  
Gene Expressions ◽  
Before And After ◽  
The Difference ◽  
Selection Of ◽  
Resistant Cells

AbstractWe report the development of a lab-on-a-chip system, that facilitates coupled dielectrophoretic detection (DEP-D) and impedimetric counting (IM-C), for investigating drug resistance in K562 and CCRF-CEM leukemia cells without (immuno) labeling. Two IM-C units were placed upstream and downstream of the DEP-D unit for enumeration, respectively, before and after the cells were treated in DEP-D unit, where the difference in cell count gave the total number of trapped cells based on their DEP characteristics. Conductivity of the running buffer was matched the conductivity of cytoplasm of wild type K562 and CCRF-CEM cells. Results showed that DEP responses of drug resistant and wild type K562 cells were statistically discriminative (at p = 0.05 level) at 200 mS/m buffer conductivity and at 8.6 MHz working frequency of DEP-D unit. For CCRF-CEM cells, conductivity and frequency values were 160 mS/m and 6.2 MHz, respectively. Our approach enabled discrimination of resistant cells in a group by setting up a threshold provided by the conductivity of running buffer. Subsequent selection of drug resistant cells can be applied to investigate variations in gene expressions and occurrence of mutations related to drug resistance.

scholarly journals Overcoming Microenvironment-Mediated Chemoprotection through Stromal Galectin-3 Inhibition in Acute Lymphoblastic Leukemia

2021 ◽  
Vol 22 (22) ◽  
pp. 12167
Author(s):  
Somayeh S. Tarighat ◽  
Fei Fei ◽  
Eun Ji Joo ◽  
Hisham Abdel-Azim ◽  
Lu Yang ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Acute Lymphoblastic Leukemia ◽  
Stromal Cells ◽  
Lymphoblastic Leukemia ◽  
High Specificity ◽  
Leukemia Cells ◽  
Cell Precursor ◽  
Cell Responses ◽  
Galectin 3 ◽  
Dose Dependent

Environmentally-mediated drug resistance in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) significantly contributes to relapse. Stromal cells in the bone marrow environment protect leukemia cells by secretion of chemokines as cues for BCP-ALL migration towards, and adhesion to, stroma. Stromal cells and BCP-ALL cells communicate through stromal galectin-3. Here, we investigated the significance of stromal galectin-3 to BCP-ALL cells. We used CRISPR/Cas9 genome editing to ablate galectin-3 in stromal cells and found that galectin-3 is dispensable for steady-state BCP-ALL proliferation and viability. However, efficient leukemia migration and adhesion to stromal cells are significantly dependent on stromal galectin-3. Importantly, the loss of stromal galectin-3 production sensitized BCP-ALL cells to conventional chemotherapy. We therefore tested novel carbohydrate-based small molecule compounds (Cpd14 and Cpd17) with high specificity for galectin-3. Consistent with results obtained using galectin-3-knockout stromal cells, treatment of stromal-BCP-ALL co-cultures inhibited BCP-ALL migration and adhesion. Moreover, these compounds induced anti-leukemic responses in BCP-ALL cells, including a dose-dependent reduction of viability and proliferation, the induction of apoptosis and, importantly, the inhibition of drug resistance. Collectively, these findings indicate galectin-3 regulates BCP-ALL cell responses to chemotherapy through the interactions between leukemia cells and the stroma, and show that a combination of galectin-3 inhibition with conventional drugs can sensitize the leukemia cells to chemotherapy.

Several Bcr-Abl kinase domain mutants associated with imatinib mesylate resistance remain sensitive to imatinib

Blood ◽  
2003 ◽  
Vol 101 (11) ◽  
pp. 4611-4614 ◽  
Author(s):  
Amie S. Corbin ◽  
Paul La Rosée ◽  
Eric P. Stoffregen ◽  
Brian J. Druker ◽  
Michael W. Deininger
Keyword(s):  
Imatinib Mesylate ◽  
Kinase Inhibitor ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Kinase Domain ◽  
Myelogenous Leukemia ◽  
Imatinib Resistance ◽  
Abl Kinase ◽  
Cellular Assays ◽  
Kinase Domain Mutations

Abstract Imatinib mesylate is a selective Bcr-Abl kinase inhibitor, effective in the treatment of chronic myelogenous leukemia. Most patients in chronic phase maintain durable responses; however, many in blast crisis fail to respond, or relapse quickly. Kinase domain mutations are the most commonly identified mechanism associated with relapse. Many of these mutations decrease the sensitivity of the Abl kinase to imatinib, thus accounting for resistance to imatinib. The role of other mutations in the emergence of resistance has not been established. Using biochemical and cellular assays, we analyzed the sensitivity of several mutants (Met244Val, Phe311Leu, Phe317Leu, Glu355Gly, Phe359Val, Val379Ile, Leu387Met, and His396Pro/Arg) to imatinib mesylate to better understand their role in mediating resistance.While some Abl mutations lead to imatinib resistance, many others are significantly, and some fully, inhibited. This study highlights the need for biochemical and biologic characterization, before a resistant phenotype can be ascribed to a mutant.

scholarly journals In vitro drug sensitivity of cells from children with leukemia using the MTT assay with improved culture conditions

Blood ◽  
1990 ◽  
Vol 76 (11) ◽  
pp. 2327-2336 ◽  
Author(s):  
R Pieters ◽  
AH Loonen ◽  
DR Huismans ◽  
GJ Broekema ◽  
MW Dirven ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Survival ◽  
Mtt Assay ◽  
Large Scale ◽  
Drug Sensitivity ◽  
Lymphoblastic Leukemia ◽  
Leukemia Cells ◽  
Response Curves ◽  
Mtt Reduction

Abstract The knowledge about drug resistance in childhood leukemias and acute lymphoblastic leukemia (ALL) in general is limited. This is because of the lack of a suitable in vitro drug sensitivity assay, which is in part due to low in vitro ALL cell survival. We recently adapted the highly efficient 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay to test cells from ALL patients and showed that its results were comparable with those of the DiSC assay, up to now the most valid but laborious assay. In this study, in vitro drug sensitivity was assessed in cells from 82 children with leukemia, 79 of whom had ALL, with the MTT assay. Dose response curves were obtained for 6-mercaptopurine, 6-thioguanine (6-TG), prednisolone (Pred), daunorubicin (DNR), vincristine (VCR), cytosine arabinoside (Ara-C), L- asparaginase (L-Asp), mafosfamide, and mustine. A cytotoxic effect of methotrexate could be detected in only a few cases. Large interindividual differences in drug sensitivity were detected. Compared with leukemia cells from newly diagnosed patients, leukemia cells from relapsed patients were significantly more in vitro resistant to 6-TG, Pred, Ara-C, mafosfamide and mustine but not to DNR, VCR, and L-Asp. Improvements of culture medium and methods to increase MTT reduction were studied. From 10 components tested, addition of insulin and bovine serum albumin to serum-containing medium improved ALL cell survival. Addition of succinate did not increase the amount of MTT reduction. We conclude that the in vitro MTT assay highly facilitates large-scale studies on drug resistance of ALL patients that can lead to rational improvements in existing treatment protocols.

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